Relaxation oscillator circuits are used to provide clock signals for applications in which a precise output signal frequency is desired. Many relaxation oscillators operate by charging and discharging reactive components and comparing the charged state variable with a preset threshold to provide for state switching of a bi-stable output defining a clock cycle. Such circuitry, however, is subject to long-term drift in the output frequency caused by drift of a bandgap or other reference circuit providing the threshold for comparator switching. Moreover, such circuits often suffer from output frequency drift caused by amplifier gain degradation over time and temperature, as well as comparator offset drift effects and power supply variation.